Keep focused agent timelines live and catch up instantly (#2196)

* fix(app): keep focused agent timelines live

Window focus was conflated with app visibility, so switching OS windows could remove the selected timeline subscription. Separate those signals, grace every visibility-driven removal, and cover retained history until authoritative catch-up completes.

* fix(app): keep timeline catch-up failures non-blocking

* fix(app): surface timeline catch-up failures

* fix(app): preserve file preview refocus

* fix(app): preserve optimistic catch-up flow

packages/app/src/panels/agent-panel.tsx

@@ -1,7 +1,15 @@
 import type { DaemonClient } from "@getpaseo/client/internal/daemon-client";
 import type { TFunction } from "i18next";
 import { SquarePen } from "lucide-react-native";
-import React, { memo, useCallback, useEffect, useMemo, useRef, useState } from "react";
+import React, {
+  memo,
+  useCallback,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+  useSyncExternalStore,
+} from "react";
 import { useTranslation } from "react-i18next";
 import { ActivityIndicator, Text, View } from "react-native";
 import ReanimatedAnimated from "react-native-reanimated";
@@ -14,6 +22,7 @@ import { AgentStreamView, type AgentStreamViewHandle } from "@/agent-stream/view
 import { ArchivedAgentCallout } from "@/components/archived-agent-callout";
 import { FileDropZone } from "@/components/file-drop/file-drop-zone";
 import { useRetainedPanelActive } from "@/components/retained-panel";
+import { SidebarCallout } from "@/components/sidebar-callout";
 import { Composer } from "@/composer";
 import { AgentModeControl } from "@/composer/agent-controls/mode-control";
 import { RewindComposerRestoreProvider } from "@/components/rewind/composer-restore";
@@ -751,6 +760,26 @@ function ChatAgentContent({
   const agentHistorySyncGeneration = useSessionStore((state) =>
     agentId ? (state.sessions[serverId]?.agentHistorySyncGeneration?.get(agentId) ?? -1) : -1,
   );
+  const viewedTimelineSync = useSessionStore(
+    (state) => state.sessions[serverId]?.viewedTimelineSync ?? null,
+  );
+  const subscribeToVisibilityCatchUp = useCallback(
+    (listener: () => void) => viewedTimelineSync?.subscribe(listener) ?? (() => {}),
+    [viewedTimelineSync],
+  );
+  const readTimelineStatus = useCallback(
+    () =>
+      !agentId || !viewedTimelineSync
+        ? ("ready" as const)
+        : viewedTimelineSync.getAgentTimelineStatus(agentId),
+    [agentId, viewedTimelineSync],
+  );
+  const timelineStatus = useSyncExternalStore(
+    subscribeToVisibilityCatchUp,
+    readTimelineStatus,
+    readTimelineStatus,
+  );
+  const visibilityCatchUpStatus = isPaneVisible ? timelineStatus : "ready";
   const hasActiveCreateHandoff = useCreateFlowStore((state) =>
     findActiveCreateHandoff({ pendingByDraftId: state.pendingByDraftId, serverId, agentId }),
   );
@@ -862,6 +891,7 @@ function ChatAgentContent({
       isArchivingCurrentAgent,
       isHistorySyncing,
       needsAuthoritativeSync,
+      visibilityCatchUpStatus,
       continuity,
       hasHydratedHistoryBefore,
     },
@@ -1004,6 +1034,7 @@ function ChatAgentContent({
     viewState.tag === "ready" &&
     viewState.sync.status === "catching_up" &&
     viewState.sync.ui === "overlay";
+  const showHistorySyncError = viewState.tag === "ready" && viewState.sync.status === "sync_error";
 
   return (
     <ChatAgentReadyContent
@@ -1023,6 +1054,7 @@ function ChatAgentContent({
       handleComposerHeightChange={handleComposerHeightChange}
       handleMessageSent={handleMessageSent}
       showHistorySyncOverlay={showHistorySyncOverlay}
+      showHistorySyncError={showHistorySyncError}
       cwd={agentCwd}
       onAttentionInputFocus={attentionController.clearOnInputFocus}
       onAttentionPromptSend={attentionController.clearOnPromptSend}
@@ -1048,6 +1080,7 @@ const ChatAgentReadyContent = memo(function ChatAgentReadyContent({
   handleComposerHeightChange,
   handleMessageSent,
   showHistorySyncOverlay,
+  showHistorySyncError,
   cwd,
   onAttentionInputFocus,
   onAttentionPromptSend,
@@ -1069,6 +1102,7 @@ const ChatAgentReadyContent = memo(function ChatAgentReadyContent({
   handleComposerHeightChange: (height: number) => void;
   handleMessageSent: () => void;
   showHistorySyncOverlay: boolean;
+  showHistorySyncError: boolean;
   cwd: string;
   onAttentionInputFocus: () => void;
   onAttentionPromptSend: () => void;
@@ -1140,6 +1174,14 @@ const ChatAgentReadyContent = memo(function ChatAgentReadyContent({
         <FileDropZone style={styles.container} disabled={isArchivingCurrentAgent}>
           {contentContainer}
 
+          {showHistorySyncError ? (
+            <SidebarCallout
+              title={t("agentPanel.states.timelineSyncFailed")}
+              variant="error"
+              testID="agent-timeline-sync-error"
+            />
+          ) : null}
+
           {composerSection}
 
           {showHistorySyncOverlay ? (